Syntaxonomy of the Robinia pseudoacacia communities in the central peri-adriatic sector of the Italian peninsula

This study presents the results of a floristic vegetational study on Robinia pseudoacacia neoformation forests in the peri-Adriatic sector of central Italy. This has allowed the characterization of these coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These currently represent the southernmost syntaxa of the Robinietea class described for the Italian peninsula, and the first syntaxonomic contribution of this class in Europe for the Mediterranean biogeographical region. We propose here the new alliance Lauro nobilis–Robinion pseudoacaciae of the order Chelidonio–Robinietalia pseudoacaciae and class Robinietea, with two new associations: Melisso altissimae–Robinietum pseudoacaciae and Rubio peregrinae–Robinietum pseudoacaciae. The new alliance Lauro nobilis–Robinion pseudoacaciae (typus: Melisso altissimae–Robinietum pseudoacaciae) brings together neoformation forests and pre-forest dominated by R. pseudoacacia in those territories with a Mediterranean macroclimate of the peri-Adriatic sector of central Italy. The optimum is found for the alluvial plain and low-slope morphologies, on soils that are moist and rich in organic matter and in areas with anthropic disturbance. On the basis of comparisons with the European context, the alliance Bryonio–Robinion described for the temperate territories of northern Italy is here validated.     

The Chrysopogono grylli-Nerietum oleandri association in Croatia as compared with other Rubo ulmifolii-Nerion oleandri communities (Tamaricetalia,Nerio-Tamaricetea) in the Mediterranean

Abstract

A new association, Chrysopogono grylli-Nerietum oleandri, situated in the south of Croatia, is proposed. According to its floristic structure, physiognomy and ecology, it belongs to the Rubo ulmifolii-Nerion oleandri alliance (Tamaricetalia, Nerio-Tamaricetea). It is the only association with Nerium oleander in Croatia. This community has developed along a temporary watercourse as a vegetation exclave (extrazonal stand) within the climazonal evergreen forest vegetation of the Oleo-Ceratonion alliance. The association has a thermophilous character and a large number of companions from the Quercetalia ilicis and Scorzonero-Chrysopogonetalia communities. This report compares the floristic composition of this association with others of the Rubo ulmifolii-Nerion oleandri alliance from other Mediterranean areas. The Croatian association is most similar to the Spartio-Nerietum oleandri association from the Ionian side of Calabria (south Italy). The syntaxonomic status of the Montenegrin association Andropogono distachyi-Nerietum oleandri was determined, and the status of the stands with Nerium oleander is discussed.     

Spatial patterns and associations of dominant woody species in desert–oasis ecotone of South Junggar Basin,NW China

Spatial patterns and associations of plant species are important for revealing how species interact with each other and with the environment, and hence have important implications for the understanding of species interaction and underlying ecological processes with apparent patterns in temperate desert vegetation. In this paper, the function g (r) was used to characterize the spatial patterns and associations of four dominant woody species in three 1-ha desert plant plots in the desert–oasis ecotone of South Junggar Basin, NW China. The complete spatial randomness null model showed four species exhibited significant aggregations at small scales (<20 m). Anabasis aphylla and Nitraria roborowskii, Haloxylon ammodendron and Reaumuria songarica were spatially positive associations at small scales with the independent null model, while A. aphylla and H. ammodendron, A. aphylla and R. songarica, R. songarica and N. roborowskii species pairs exhibited negative associations at small or moderate scales (20–60 m) in our study. The random labeling null model showed that dead standing plants of A. aphylla were largely determined by the combined effects of intra- and interspecific competition. In addition, the results also indicated that the two main factors of habitat heterogeneity and sandy desertification play important roles in determining spatial distribution patterns and associations of woody species in the desert–oasis ecotone of South Junggar Basin. Thus, the differences of species features in spatial patterns and associations should be paid more attention when planning afforestation and developing conservation strategies.     

Major plant communities of the Carson Desert (Nevada), North America's coldest and driest desert

This paper describes the vegetation of the Carson Desert (Nevada, USA) based on a phytosociological analysis of its major plant associations, as determined by the Braun-Blanquet method. Diagnostic tables, climatic, edaphic, and biogeographical data were used to establish floristic affinities among identified plant communities and to interpret their distributions in zonal gradients. Their syntaxonomic positions in the classes Allenrolfeetea occidentalis and Artemisio tridentatae–Juniperetea osteospermae, and in the new class Sarcobatetea vermiculati were also established. Three associations (Atriplici confertifoliae–Sarcobatetum baileyi, Atriplici canescentis–Psorothamnetum polydenii, and Suaedo moquinii–Sarcobatetum vermiculati) are described here for the first time along with the order Sarcobatetalia vermiculati and the alliance Sarcobation vermiculati.     

The urban woods of Rome (Italy)

ABSTRACT

A phytosociological study of the urban woods of Rome is described. Six syntaxonomical types were identified: 1) Orno-Quercetum ilicis, an edaphic-xerophytic variant of the natural potential vegetation of the city (deciduous Quercus sp. pl. woods); 2) Aquifolio-Fagetum carpinetosum betuli, in the northern slopes of alluvial valleys; 3) Q. suber and Q. pubescens wood, ranked in Quercetalia pubescenti-petraeae order 4) Quercetum ilicis galloprovinciale suberetosum; 5) coppice of Q. cerris and Q. frainetto, which belongs to the Teucrio siculi-Quercion cerridis alliance; 6) mixed mesophile wood of Q. cerris and Ostrya carpinifolia which can be considered a transition between the Doronico-Fagion and the Teucrio siculi-Quercion cerridis alliances. All of these six woody vegetation types are characterised by the large penetration of Mediterranean species belonging to the Quercetea and Quercetalia ilicis and the middle-European ones of the Querco-Fagetea. This mosaic of species exemplifies the bioclimatic characteristics of Rome, which is situated in a Mediterranean transitional region.     

Synanthropic vegetation of the <Emphasis Type="Italic">Eragrostion cilianensi-minoris</Emphasis> alliance in the Czech Republic

A synthesis of the alliance Eragrostion cilianensi-minoris in the Czech Republic is presented on the basis of 82 relevés including new unpublished data. A TWINSPAN classification and detrended correspondence analysis were used to identify the main vegetation types included in the alliance Eragrostion cilianensi-minoris. A syntaxonomic revision of the data set revealed five associations of the alliance: Digitario sanguinalis-Eragrostietum minoris, Portulacetum oleraceae, Eragrostio poaeoidis-Panicetum capillaris, Cynodontetum dactyli, and Hibisco trioni-Eragrostietum poaeoidis. The latter was recently found in several arable fields in Southern Moravia (Czech Republic) and was newly characterized.     

New syntaxa for the prodrome of Italian vegetation

The aim of this study is to provide new syntaxa for the Italian vegetation checklist. For the class Rhamno–Prunetea which includes the class Paliuretea the new alliance Rhamno saxatilis–Paliurion spinae-christi is described, that is included in the order Paliuretalia spinae-christi with a central-western Mediterranean and sub-Mediterranean distribution. Otherwise, the more thermophilous Paliurus spina-christi vegetation is included in the new suballiance named as Oleo sylvestris–Paliurenion spinae-christi within the alliance Oleo–Ceratonion of the class Quercetea ilicis. For the class Trifolio–Geranietea medii, a new alliance named Hyperico calabricae–Asphodelion macrocarpi is proposed here.     

Revision of the central Mediterranean xerothermic cliff vegetation

Questions

What are the syntaxonomic and synchorological patterns of the xerothermic chasmophytic vegetation in the central part of the Mediterranean Basin? What are the diagnostic species of the high‐rank syntaxa of Asplenietalia glandulosi, Onosmetalia frutescentis and Centaureo dalmaticae‐Campanuletalia pyramidalis?

Location

Mediterranean coastal and subcoastal areas of southern France, Italy, Malta, Slovenia, Croatia, Bosnia and Herzegovina, Montenegro, Albania and of mainland Greece.

Methods

The data set of 1,261 published relevés was analysed using hierarchical clustering (Flexible Beta method), involving a series of data transformations. Indicator species analysis was used to select the best dendrogram solution and identify diagnostic taxa of the main clusters. The dendrogram was interpreted from a syntaxonomic point of view, using nomenclatural type relevés as a basis. The NMDS ordination was performed in order to visualize the floristic relationships among associations and high‐rank syntaxa. MRPP was used to test for differences among alliances.

Results

The classification revealed four main clusters of relevés representing the chasmophytic vegetation of southern France, Sardinia and the northwestern part of Italy (Asplenienalia glandulosi/Asplenietalia glandulosi), the southwestern part of Italy and Malta (Tinguarrenalia siculae/Asplenietalia glandulosi), the Adriatic Basin area (Centaureo dalmaticae‐Campanuletalia pyramidalis) and the southern Balkans (Onosmetalia frutescentis). The NMDS ordination confirmed the overall pattern, while MRPP showed significant differences among the alliances of the above‐mentioned orders and suborders. The lists of diagnostic taxa of the high‐rank syntaxa were revised according to a supra‐national perspective.

Conclusions

The new syntaxonomic scheme provides a comprehensive overview of the chasmophytic vegetation of the central part of the Mediterranean Basin. This scheme mostly matches the recently published EuroVegChecklist, but also exhibits important novelties concerning the syntaxonomic position of some alliances (Dianthion rupicolae, Centaureion pentadactyli, Arenarion bertolonii and Caro‐Aurinion), and the floristic and chorological relationships among high‐rank syntaxa, with new revised sets of diagnostic taxa. This revision might be useful for further small‐scale phytosociological studies.

     

The Pinus halepensis Mill. forests in the central-eastern European Mediterranean basin

The Pinus halepensis Mill. forest vegetation of the central-eastern European Mediterranean basin (France, Italy, Croatia, Albania, Greece) is described here. This study was carried out considering published and unpublished phytosociological data, with the organisation of a systematic classification (syntaxonomic scheme) of the order Pinetalia halepensis according to the principal floristic variations, at multiple spatial scales and according to the physiognomic–structural, floristic, ecological and biogeographical characteristics. Five alliances and 25 associations are recognised.     

Syntaxonomic revision of chasmophytic vegetation of the Centaureo cuspidatae-Portenschlagiellion ramosissimae (Southeastern Adriatic)

Abstract

The Centaureo-Portenschlagiellion describes the cliff vegetation of the Southeastern Adriatic. This habitat type harbours many endemic taxa and has a high value for biodiversity conservation. Notwithstanding its importance, knowledge of the syntaxonomy of this alliance is still poor. This article aims at revising the synchorological, coenological and floristic relationships of the associations of the Centaureo-Portenschlagiellion. The revision is based on a data set of 103 relevés of Mediterranean xerothermic cliffs from Croatia, Bosnia i Herzegovina and Montenegro. The relevés were clustered by using the Flexible beta method. An indicator species analysis was used to identify the diagnostic taxa of the main clusters of relevés and non-metric multidimensional scaling ordination was undertaken to visualize the floristic relationships among them. Results revealed that only seven associations belong to the Centaureo-Portenschlagiellion, whereas the others already described in phytosociological literature were invalidly described or should be treated as syntaxonomic synonyms of the previous ones. Two associations (Inulo-Centaureetum cuspidatae and Portenschlagiello-Campanuletum portenschlagianae) were reduced to the rank of subassociations of the Moltkio-Inuletum verbascifoliae. Two other subassociations were described for the first time. Data provided with this revision may be considered as essential base-line information that should aid in evaluating the state of this vegetation type in the future.     

Variation in the riparian landscape of the Segura River Basin,SE Spain

Abstract. The woody and shrubby riparian vegetation of the Mediterranean Region of Spain shows a progressive displacement from the Querco-Fagetea, typical of Central Europe, towards the Nerio-Tamaricetea, which has its maximum expression in North Africa. We studied the occurrence of 107 riparian plant communities on 52 locations in the Segura River Basin (SE Spain) and their presumed relation to variation in rainfall and temperature. On the basis of agglomerative clustering and Redundancy Analysis (RDA) three riparian vegetation complexes were identified and characterized by (a) Central European-related temperate communities, (b) predominantly North African riparian communities and (c) a combination of both community types, respectively. North African communities predominated in the lower stretches of the Segura Basin, probably due to the prevailing semi-arid bioclimate.     

Contribution to the knowledge on relic Stipa spp.-dominated ultramafic grasslands of the Central Balkans

The heterogeneity of the ultramafic vegetation of the Central Balkans is rather great. Although this vegetation has been continuously investigated, some gaps are still to be filled. For example, the lack of available data on ultramafic vegetation of the Republic of Macedonia is evident. In that light, we have investigated different relic Stipa species-dominated dry grasslands over ultramafic bedrock. Twenty relevés were made and compared to the similar vegetation types (i.e. Potentilla visianii, Centaureo kosaninii-Bromion fibrosi, “Thymion jankae”, Saturejo-Thymion and Alyssion heldreichii) by means of numerical analyses. We distinguished one new association and one informal community, providing them with diagnosis and lists of diagnostic, constant and dominant species. We also determined their syntaxonomic positions and relations to ultramafic syntaxa from the neighboring countries.     

Characterisation of alternative stable vegetation assemblages in a mesic savannah in Kenya

The phenomenon of sharp boundaries between distinctive vegetation types occurring under the same climatic conditions has often been interpreted by plant ecologists to characterise alternative stable states (ASS). The phenomenon may be relevant in explaining two strikingly different vegetation formations (broad-leaved nonspiny Combretum and fine-leaved spiny Acacia) co-occurring in mesic savannah of southeastern Kenya. We hypothesise that the two vegetation within southeastern Kenya ecosystems represent ASS whose transition may be a response to soil characteristics switch. To explore our hypothesis, we analysed empirical field data of woody species and soil characteristics from 57 plots that included 25 from Combretum and 32 from Acacia vegetation formations. We compared floristic composition and soil characteristics between the two systems and correlated edaphic statuses and vegetation states. We encountered 2,749 woody plant individuals, representing 115 species, 87 genera and 40 families. We found that the two vegetation had discrete woody species composition and soil characteristics, and also a significant species–edaphic association. The results are consistent with the ASS theory demonstrating that soil characteristics are among the important micro-environmental filters driving and maintaining woody vegetation mosaics in the tropics. Importantly, understanding ASS has ramifications for sustainable utilisation of woody plant resources in East African savannahs.     

Studi sulla cariologia delle asclepiadaceae

Summary

The author examines the sole station so far found in Sardinia of Satureja Thymbra Willd., a species common only in the Eastern Mediterranean, with a range including at the western extreme the islands of the Ionian sea and the vicinity of Derna in Cyrenaica, except for the isolated station described on Mount San Michele near Cagliari.

In this station, few woody and numerous herbaceous species make up the association with S. Tymbra, which in the Eastern Mediterranean forms part of the phrygana, according to some Authors, or of the batha according to others, this latter being a gradation lower ecologico-climatically than the garigue and the phrygana. Phrygana and batha populations do not exist in the Western Mediterranean.

The San Michele station might be conveniently classified as a tomillares owing to the presence of certain Labiatae species, but because the more characteristic species of this association are lacking as compared with the Iberian Peninsula, the Author considers this population to be of the steppe type with Labiatae in which many of the steppe Graminaceae are present, though again not the most characteristic.

The Author then examines the genetic and phylogenetic aspects of the species, which he considers to be linked with the geological events of the period corresponding to the existence of the Tyrrhenian continent, between the upper Miocene and the lower Pliocene (Pontian).     

Syntaxonomic diversity as an indicator of ecological diversity — case study Vranica Mts in the Central Bosnia

Syntaxonomic diversity (SD) represents the number of plant communities (phytocoenoses) in certain area. Plant communities as organized systems of populations of various coexisting plant species inhabiting same or similar habitat in the function of time. SD is one of the best indicators of the state and potential carrying capacity of every ecosystem and an attribute of total ecological diversity. In general, level of syntaxonomic diversity indicates habitat heterogeneity and diversity. This could have significant importance in the categorization of habitat values in accordance with European Nature Information System (EUNIS) criteria. The results presented in this paper indicate without any doubt high natural values of mountain range Vranica in Bosnia and Herzegovina. One of the best proofs is an extremely high level of syntaxonomic diversity. In this area covering just 288 km², vegetation is differentiated into 9 formations, 28 classes, 44 orders, 73 alliances and 165 associations. This represents 85% of all classes, 73% of all orders, 65% of all alliances, and 53% of all associations of vegetation in Bosnia and Herzegovina, or 35% of all classes in vegetation diversity in Europe. Going from the level of class to the level of order, the number of syntaxa increases for 61%, from order to alliance for 60%, and from alliance to association for 44.24% (average 55%). SD index is very high and it is 0.5729. This means that on each km² contains 0.5729 syntaxa.     

Nomenclatural remarks on the chasmophytic vegetation of the Centaureo-Campanuletalia

The thermophilous chasmophytic vegetation on limestone of the Adriatic Region has been arranged in the endemic order Centaureo-Campanuletalia (class Asplenietea trichomanis). The distribution range of the order covers a large area around the Adriatic Sea – from the south and north east of Italy to Slovenia, Croatia, Bosnia i Hercegovina, Montenegro and Albania. The Centaureo-Campanuletalia or its subordinated syntaxa are quoted in the main syntaxonomic synopses of the Region as well as in technical reports. The critical analysis of the nomenclature of the order, based on the International Code of Phytosociological Nomenclature (ICPN), showed many invalid or incorrect names while it is evident that the usage of correct names in scientific literature is crucial, both for the advances of syntaxonomic knowledge and their application for practical purposes. This paper presents a revision of the nomenclature for the Centaureo-Campanuletalia and related syntaxa in order to stabilize this nomenclature at least at alliance level. As a result, three syntaxa were validated (Centaureo dalmaticae-Campanuletalia pyramidalis, Centaureo cuspidatae-Portenschlagiellion ramosissimae, Inulo verbascifoliae-Centaureetum cuspidatae) and five others were lectotypified.     

Contribution to the flora of Pakistan: Hedysarum alii and H. shahjinalense spp. nov. (Fabaceae) and three new records

Two new species of Hedysarum, H. alii Haidar Ali & Qaiser sp. nov. and H. shahjinalense Haidar Ali & Qaiser sp. nov. are described from Chitral in Pakistan. As far as known, both new species are endemic to Chitral and are categorized as ‘Critically Endangered’ (CR). In addition, three other species of Hedysarum are recorded from Pakistan for the first time, viz. H. volkii Rech. f., H. brahuicum Boiss. and H. sericeum M. Bieb. These are also ‘Critically Endangered’ (CR) at a national level. A key to all 12 species of Hedysarum occurring in Pakistan is provided.     

Vegetation and songbird response to land abandonment: from landscape to census plot

While intensification of human activities and its ecological effects in many natural areas have recently received much attention, land abandonment in marginal areas is still the largely ignored side of a process rooted in the same socioeconomic context. Decreasing human impact in marginal rural areas often triggers a recovery of seminatural vegetation. Over a period of 25 years, we studied the changes in landscape and vegetation structure that followed land abandonment in a traditional Mediterranean mosaic of crops, grasslands, shrublands and woodlands, and assessed their effects on songbird occurrence and distribution. We combined an analysis of vegetation changes based on aerial photo interpretation with an analysis of bird censuses from 1978, 1992 and 2003 at two spatial scales: landscape and census plot (respectively 2800 and 3 ha). The perceived temporal changes in the vegetation were scale dependent. At the landscape scale, open habitats tended to disappear and woodlands matured. The contrasts in vegetation structure that defined habitat patches at the onset of the study tended to disappear. There was an overall shift of the bird community in favour of woodland species. At the scale of the census plot, however, the colonization by woody vegetation of patches formerly characterized by a homogeneous grass cover increased the local diversity of the vegetation, at least temporarily. Of seven species dependent on open habitats, the occurrence rate of five species significantly decreased, whereas it increased for two species: woodlark (Lulula arborea) and melodious warbler (Hippolais polyglotta). This increase was linked to the transitional increase in local vegetation diversity. In patches originally dominated by woodlands, local vegetation diversity decreased as woody vegetation expanded into clearings. The occurrence rate significantly increased for seven species relying on closed woodlands, while it decreased for two woodland species. As most species of high conservation profile in the Mediterranean are tied to open or to heterogeneous transitional habitats, these trends raise questions concerning their persistence in the future.